batman_adv: batadv0: The MTU of interface veth481 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface veth481 (retrying later): interface not active ------------[ cut here ]------------ batman_adv: batadv0: Adding interface: veth473 WARNING: CPU: 0 PID: 7080 at net/batman-adv/bat_iv_ogm.c:555 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:555 [inline] WARNING: CPU: 0 PID: 7080 at net/batman-adv/bat_iv_ogm.c:555 batadv_iv_send_outstanding_bat_ogm_packet+0x5a2/0x680 net/batman-adv/bat_iv_ogm.c:1797 Kernel panic - not syncing: panic_on_warn set ... batman_adv: batadv0: The MTU of interface veth473 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. CPU: 0 PID: 7080 Comm: kworker/u4:0 Not tainted 4.14.156-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 batman_adv: batadv0: Not using interface veth473 (retrying later): interface not active panic+0x1f9/0x42d kernel/panic.c:183 __warn.cold+0x2f/0x2f kernel/panic.c:547 report_bug+0x216/0x254 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:177 [inline] fixup_bug arch/x86/kernel/traps.c:172 [inline] do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295 device veth473 entered promiscuous mode do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963 RIP: 0010:batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:555 [inline] RIP: 0010:batadv_iv_send_outstanding_bat_ogm_packet+0x5a2/0x680 net/batman-adv/bat_iv_ogm.c:1797 IPv6: ADDRCONF(NETDEV_UP): veth473: link is not ready RSP: 0018:ffff88808d51fcc8 EFLAGS: 00010297 RAX: ffff88809c3d8340 RBX: ffff88809f494ac8 RCX: ffff88809c3d8bc0 RDX: 0000000000000000 RSI: ffffffff87790c60 RDI: ffff8880994a60e8 RBP: ffff88808d51fd38 R08: 0000000000003a54 R09: ffffffff88ca1860 batman_adv: batadv0: Interface activated: veth473 R10: ffff88809c3d8be8 R11: ffff88809c3d8340 R12: ffff88808fe44e00 R13: ffff88809f494a80 R14: ffff8880956eb040 R15: ffff8880994a6080 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 batman_adv: batadv0: Interface deactivated: veth473 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Kernel Offset: disabled Rebooting in 86400 seconds..